Nov.. 1922
T H E JOURNAL OF INDUSTRIAL A N D ENGINEERING CHEMISTRY
A compound is described by Mills and Pope4 which was prepared by the condensation of 6-acetaminoquinafdineethiodide and quinoline ethiodide with formaldehyde and alkali and crystallizes in minute green needles. It sensitizes at 6300 to 6800 and more weakly a t 5200 to 6300, and thus appears to he an entirely different compound from that described here
KBYPTOCYANINE This dye was prepared by the condensation of lepidine ethiodide.s On recrystallizing from chloroform, small bronze
Pic-. 4 - K n u ~ r o c ~ n x i a s
crystals are obtained. On trial this proved to he the most remarkable sensitizer yet discovered. A great deal of time was expended in purifying it to prevent a fogging action on the emulsion, since when tested in the usual concentration, 1 in 25,000, it gave severe fog, though sensitizing with great power with a maximum at 76Cpp. It was found, however, that the dye was being used in far too great a concentration, and by the use of only '/*a the amount required for pinacyanole excellent. results were obtained. The spectrum I
Phal. I . , 40 (1920). 253.
* E. 0.Adams and H . L. Haller. .IAm. . Chcm. Soc.. 1% (1920).2661.
1061
is shown in Fig. 4. For bathing solutions a concentration of 1 in 500,Mx) is recommended. The addition of either ammonia or alcohol was found to be a disadvantage. Tests were made for the extension of the spectrum with kryptocyanine into the extreme infra red. It was found that although its maximum is a t a considerably longer wave length than that given by dicyanine, and although up to 850p@s sensitizing power is greater than that of dicyanine, yet beyond this point dicyanine shows a greater sensitizing power, and above W p p kryptocyanine is almost useless, while dicyanine, employed according to the directions given by Dr. Meggers, is still effective. Nevertheless, kryptocyanine represents a very great advance in the preparation of photographic materials sensitive to the extreme red. Sinoeit confers no green sensitiveness and, indeed, the materials sensitized with it have very little sensitiveness below 680pp, infra red effects in ordinary photography can be obtained hy the use of a strong yellow filter only, and, employed in this way, it is possible to give very short exposures, one second at f / % being quite satisfactory in bright sunlight. The results obtained are those characteristic of photography in the infra red, blue skies appearing dark and green foliage very bright, so that a free covered with spring leaves appears as if in blossom and the grass on the ground as if it were snow. It is probahle that the dye wiU have applications in 8%. tronomy. At the present time, stars are classified by their color index, this being the relation of the photographic magnitude determined in the violet to the photo visual magnitude determined in the yellow-green, and determination of the extreme red magnitude at 770pp by the use of kryptocyanine will probably extend the value of such studies. Undoubtedly nwnerous other applications will be found for this dye.
Sources of Moving Picture.Films A large number o l films produced and distributed by the United States Department of Agriculture =re described in Deparfment Cirolkir 233, which may be obtained from the Superintendent of Documents at a cost of 5 cents a copy. These films are intended primarily for the use of extension and field workers of the department and 01 officialh cooperating institUtiOnS, but others may make special arrangements to borrow Or to buy copies. The Publicity Bureau of E. I. du Pont de Nemours & Co., Inc., has at its disposal moving pictures of the war plants, now dismantled, which may be of interest to engineering societies
and technical schools. The films, which are all short, are as follows: Old ~ i e k o r ySmokeles . Powder Hopewell.Va., GuncottonPlant
Pennimao, va., Shell-loading Planant Carney'sPoint. N. J.,SmokelesnPowder
A film of the du Pont Dye Works at Deepwater Point, N. J.. is also available. No charge is made for the use of these films. . The Industrial Department of the Young Men's Christian Association, 347 Madison Ave., New York. N. Y., is acting as the distributor of industrial and educational moving picture films for the companies listed below. Information in regard to the films may he obtained from the Association.
Durham Hosiny Milk Einemann Magneto Corp. Eisoer. Sigmund Co. Elliott Co. Fruit Despatch Co. Girl Seovts of America Grnton & Knight Mfp. Co. Oreirt Mfg. Co. Hwver Suction Sweeper Co. Howard J . W. & A . P. Co. Ioteroat'ionnl Herveste; Co. International Mercantile Marine Co. International Silver c o . Kirkman & Sons Koehring Machine Co. K c w ~ e S. . S.. Co. Lamson company Long Bell Lumber Co. Mint Produets Co. M d e r Safe Co. National Automatic Sprinkler Assn. National Biscuit Co. National Carbon Co. National Coffee Roasters Aasn. National Electric Light Am.. Nationnl Lead Co. National Life Preserver Co. Natiooei Tma Cotts Soeiety North Gnst Eleetrk Co. Northwestern Chemleai Co.
Southern Lumber Co. Stafford, S. S., Inc. Standard Oil Co. Standard Pnevmatic Action Co. Stearnson E. A. & Co., Ine. Stone & Webrtk Swift & Co. U. S. Cast 1100 Pipe & Foundry Co. Wayne Oil Tank & Pump Co. Welch Grape Juice Co. Western EIectnc Co. Westinghome Electric & Mfg. Co. Wilkcs-Barre Pa. Chamber of Commerce Winchester E. A. 'Co. women's college Of Conrtantinople Wwd J. R. & Sons Wrigdt F 'k. Shoe CO. Y a w n & & E;be Mfg. Co.
